1. Field of Invention
The present invention relates to an ink-jet system, and more particularly to a pneumatic ink-jet system, which provides stable air pressure to jet ink while printing.
2. Description of the Related Art
A conventional pneumatic ink-jet system is applied in an inkjet printer to control ink to be released from an inkpot through a print head while operating the inkjet printer. An air pump is used in the conventional pneumatic ink-jet system to directly control pressure inside the inkpot such that quantity of ink in the print head maintains appropriate to keep the print head in a wet state.
However, pressure generated by the air pump is usually unstable as shown in FIG. 3 because the air pump vibrates all the time. The unstableness of the pressure generated by the air pump may lead the print head to be over-wet or too dry, such that the quality of printing is influenced badly.
Moreover, in the conventional pneumatic ink-jet system, the surface of the ink inside the inkpot is higher than the position the print head. That is a good method to help control the pressure inside the inkpot but only for normal, standard prints. The method can not be applied in a large format inkjet printer.
To overcome the shortcomings, the present invention provides a pneumatic ink-jet system to mitigate or obviate the aforementioned problems.